Side wall fluid sampler



Sept. 15, 1959 c N SIDE WALL FLUID SAMPLER Filed April 16, 1956 INVENTOR.

Durward 5. M Mahon, BY

AZZOBNEX X nates the main body of the tool.

SIDE WALL FLUID SAMPLER Durward B. McMahan, Duncan, kla., assignor, by mesne assignments, to Welex, Inc., Fort Worth, Tex., a corporation of Delaware Application April 16, 1956, Serial No. 578,458

3 Claims. (Cl. 166100) This invention generally relates to apparatus for obtaining fluid samples from earth formations penetrated by a well bore and more particularly relates to an earth formation fluid sampling apparatus adapted to be lowered into the well bore by means of an electrical cable and be actuated from the earths surface.

The objects and advantages of the invention will be more readily apparent from the following detailed description, taken in connection with the accompanying drawings, in which:

Figure 1 is a view in side elevation of the tool embodying the invention and showing it positioned opposite a formation to be tested;

Figure 2 is a detailed vertical sectional view of the tool, taken at 22 of Figure 4;

Figure 3 is a vertical sectional view of the tool in position to take a sample; and showing alignment of fluid passageways;

Figure 4 is a transverse sectional view taken at 44 of Figtu'e 3;

Figure 5 shows a portion of the tool in the position it occupies after the sample has been obtained; and showing the fluid passageways out of alignment;

Figure 6 is an enlarged sectional view of a brass wedge ring employed to hold a gun barrel in extended position.

The tool is illustrated in the drawing, Figure l, as designed for use in an uncased bore hole 10. The corresponding parts in the different figures of the drawing are designated by the same numerals.

Referring first to Figure 1 of the drawing, 12 desig- It is preferably of cylindrical shape, and is suspended in the bore hole by a single conductor electrical cable 16. It may be positioned against wall 10 by any suitable wall contact means such as drag springs 14. Numeral 18 generally refers to a gun apparatus and 20 refers to a suitable sample receiving reservoir or chamber which can be adapted at 22 to receive a pressure recording device (not shown), if it is desired to record the formation pressure while the fluid sample is obtained.

As shown in Figure 2, a resilient sealing pad 26 is employed to prevent contamination of the gun apparatus 18 by well bore debris while the tool is lowered into the well.

The details of gun apparatus 18 are shown in Figures 2, 3 and 4.- This includes a housing 19, which has a flat surface 1%. This housing is mounted for limited rotation in the main body 12 of the tool by the pivot means or trunnions 46, and is normally held in the horizontal poistion by shear pin 48. Slidable in a chamber of housing 19 is a gun barrel 30 having a muzzle 28, and a closed rear section including an external shoulder 45. Explosive powder grains are shown at 32 and the arrangement is such that when the powder is ignited, the barrel 30 is thrust outwardly through a reduced opening disposed in the forward end of housing 19.

Barrel 30, shoulder 45, and a forward shoulder formed tatcs 211:6 flf on the cable 16.

by the chamber and reduced opening of housing 19 define barrel 30. At the forward end of chamber 43, a wedge ring 44 is placed. As shown in Figure 6, this ring 44 has a triangular cross-sectional shape and is of a softer material than that of the barrel 30.

'Within the housing 19, there is a small passageway 42, leading to an internal annular groove 40a near its forward end. This communicates with a vertical passageway 40 in the main body 12 of the tool, so long as the housing 19 is in the horizontal position, as shown in Figure 2 and Figure 3. This passageway 40 connects sample chamber 20, through a check valve 24, to the fluid passageway 42 of housing 19.

Annular groove 40a is sealed with respect to the barrel 30 by 0 rings 38. When the barrel 30 is in the position shown in Figure 2, there is thus no chance of the chamber 20 being contaminated with well fluid.

Fluid can enter the chamber 20 when the barrel 30 is thrust forward to the position shown in Figure 3. To accomplish this, the rear end of the barrel 30, just in front of the structure which provides the chamber for the powder 32, is provided with fluid entry ports 41. When the barrel 30 is fully advanced, these ports 41 match up, horizontally, with groove 40a, so that fluid can then flow from the formation 34 into the chamber 20.

It should also be mentioned that ports 36 provide means to exhaust the resulting gases upon ignition of powder grains 32.

In order to obtain a fluid sample from a selected formation 34, the tool 12 is run into the bore hole It is positioned in the bore hole so that the gun apparatus 18 is opposite the formation 34 to be tested. The resilient sealing pad 26 will then be pressed against the well bore wall 10, by wall Contact means 14, and this pad 26 will prevent cuttings and materials carried in the drilling fluid from entering barrel 30 through the muzzle 28.

Since the barrel 30 is then in the position shown in Figure 2, the annular groove 40a, communicating with passageways 42 and 40, is closed by the barrel 30 and the 0 rings 38. Grains of powder 32 are ignited from the surface in the conventional manner by causing current to flow through'the conductor of the cable. The resulting gases of the explosion force barrel 30 through sealing pad 26 and into formation 34, the parts then taking the position shown in Figure 3. The action being that of a sleeve valve, wherein the barrel acts as a sleeve sliding' within housing 19 and aligning the ports 41 with the annular groove 40a and the passageway 42. The explosion gases are exhausted into the well bore through ports 36 as the gun barrel 30 assumes the position as shown in Figure 3. The 0 rings 38 seal around barrel 30 to prevent intrusion of well bore fluids and pressures into conduit 40 and from passing around the barrel 30 into the muzzle 28. The barrel 30 is then held'in' extended position in the formation by frictional engagement with the wedgering 44.

The explosion gases propelbarrel 30 forward with great force and acceleration. The distance traveled is relatively short and, unless precautions are'taken, the

barrel 30Ltends to rupture just forward of shoulder 45.

Toupreve'nt' this rupturing, aconstructio'n employinga hydraulic cushion is* used.'- As mentioned above, the i chamber 43 is filled with well bore fluids through ports 36 and 36a as the tool is lowered into the well. When the barrel 30 is propelled forward, shoulder 45 acts as a piston on such well bore fluids and exhausts them through along the-senlarged portionrof the. barrel and. outof .the.

annular chamber.43,@ through the-ports 36a.. 'Ihisfluid thus acts as a hydraulic brake. Such action as described,

prevents rupture of barrel 30.-

With barrel 30in the extended or fiXd.,pOS1tlOl1..flS

shownin Figure 3, the ports 41 fbarrel 30 are aligned with the annular groove40a, and by way of passagewayv 42 are .in communication with passageway 40. Formationpressure forces fluids fromsaid .formation.34 through muzzle 28, ports 41, passageway 42, passageway 40, and

valve 24 into sample-receiving chamber 20. The-check valve 24- retains fluids in' the chamber 20. After the desired sample is obtained, the-entire tool-is pulled .upward and out of the hole by means of the cable .16. As thetool is pulled upward, the housing 19 rotates around trunnions' 46, shearing pin 48. rotates, passageway 42-is displaced out of alignment with conduit 40, as shown in Figure 5, and the flat surface 19a of housing 19 closes conduit40 in a rotatable valve action, thereby sealingsaid conduit140 from. intrusion of well bore fluids and pressure as the tool-is removed from the hole and thereby maintaining; a. pure 'samplein sample chamber :20 by means of check valve 24. Thenthe fluid samplecan be removed and tested.

Having described my invention in detail, it is readily. apparent that various changes and adaptations can be made without departing from the spirit of theinvention and-.the scopeof the'annexed claims.

1. A well formation sampling apparatus comprising, anelongated body containing a sample reservoir,- an elongated housing mountedwithin said body ,in a first transverseposition and adapted tobe rotated to a second posi-- tion, a chamber disposed within said housing, a chamber opening of reduced diameter disposed in .said. housing which extends through a forward end of said housing, a

chamber shoulderdisposed between said chambertand said chamber opening, a firstpassagewaydisposed-through said housing from said chamber opening to said body, a second passageway disposed through said body from said sample reservoir to said housing-whereby said first and second. passageways are in communication when said housing is disposed in said first position and not in com.- munication when said housing is rotated-to, said second position, a hollow sampler barrel having ajclosedrear section forming an external shoulder onxsaid barrel, saidbarrelv being adapted to be: moved through said chamber opening from a retracted position within said chamber to an extended position,-a third passageway disposedthrough the wall of said barrel, said first passage- I way'beingclosedrbysaid barrel when said barrel is in said retracted position'and said-first andthird passage;

ways being in communication when said barrel is in said extended position, and'means disposed in said chamber at the rearof said barrel for forciblymoving said barrel fromsaid retracted to said extended-position.

2., A well formation sampling apparatus'comprising, an

to .saidbody, a second passagewaydisposed insaidbody from said .sample reservoir tosaid housing, means to provide fluid communication between said first, and .second.

As the housing 19- munication. when said housing is disposed in said first 30 passageways, a hollow sampler :barrel havinga closed rear section disposed within said chamber, said rear section forming an external shoulder on said barrel, said barrel being adapted to be moved through said chamber opening from a retracted position within said chamber to an extended position, a wedge ring disposed between said barrel shoulder and said chamber shoulder for retaining said barrel in said extended position when forcibly movedthereto, a third passageway disposed through the wall of said barrel, said first passageway being closed bynsaid barrel whensaid barrel is in said retracted position-and said first-and third'passageways being in communication when said barrel is in said extended position, and=means disposed within said chamber at-the rear of said barrel for forcibly moving said barrel from said retracted to said extended position.

3. A Well formation sampling apparatus comprising, an elongated body containing a sample reservoir, an elongated housing, mounted .within said body in a first transverse. position and adapted to be rotated to a second position, a chamber disposed within said housing, a chamher opening of reduced diameter disposed in said housing which. extends from said chamber through a forward end of said housing, a chamber, shoulder disposed between said chamber and said chamber opening, a firstpassageway disposed through said housing from said-chamber opening. to said body, a second passageway disposed through said body from said sample reservoir to said housing saidfirstand second passageways being in composition and not in communication when said housing is rotatedto said second position, a hollow sampler barrel having a closed rear section disposed within said chamber, said rear section forming an external shoulder on said barrel,v said barrel being adapted to be moved through said chamber opening from a retracted, position to an ,extendedposition, a. wedge ring disposed between said barrel shoulder and said chamber shoulder to retain said barrel .in said extended position when forcibly moved thereto,-a third. passageway disposed through the wall of said barrel, said first passageway being closed by said barrel when said barrel is in said retracted position and said first and third passageways being in communication when said barrel is in said extended position, an annular chamber. enclosed within said chamber by said barrel, said barrel shoulder, andsaid chamber shoulder, a fourth passageway disposed through the wall of said housing near said chamber shoulder for receiving fluid into said annular chamber and for selectively'restricting displacement of-saidfluid from said annular chamber upon movement of said barrel :toward said extended position, ex plosive means disposed in said chamber at the rear of saidv barrel-for forcibly moving said barrel from said retracted to said extended position, a fifth vent passageway disposed within the wall of said housing at the rear of said barrel when said barrel is positioned atsaid extendedposition, resilient means mounted on said body across the front. of said barrel for excluding solid debris from said barrel interior, and means mounted on said body to urge said barrel into proximity with a well bore wall.

References Cited in the file of this patent UNITED STATES PATENTS 2,509,883 Rolshausen et al May 30, 1950 2,511,508 McClinton June 13, 1950 2,545,306 Pollard Mar. 13, 1951 2,674,313 Chambers Apr. 6, 1954 3 2,717,760 Bannester Sept. 13, 1955 2,809,805 Laval Oct. 15, 1957 2,809,806 Laval Oct. 15, 1957 

